Vulnerability · Published Mar 23, 2026 · Assigned by GitHub_M
CVE-2026-33174Rails Active Storage has a possible DoS vulnerability when in proxy mode via Range requests
Medium 6.6
In plain English
A medium-severity security flaw in activestorage from rails. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 50% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
Active Storage allows users to attach cloud and local files in Rails applications. Prior to versions 8.1.2.1, 8.0.4.1, and 7.2.3.1, when serving files through Active Storage's proxy delivery mode, the proxy controller loads the entire requested byte range into memory before sending it. A request with a large or unbounded Range header (e.g. `bytes=0-`) could cause the server to allocate memory proportional to the file size, possibly resulting in a DoS vulnerability through memory exhaustion. Versions 8.1.2.1, 8.0.4.1, and 7.2.3.1 contain a patch.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | rails | 2:7.2.2.2+dfsg-2~deb13u2 | DEBIAN-CVE-2026-33174 |
| Debian:14 | rails | 2:7.2.3.1+dfsg-1 | DEBIAN-CVE-2026-33174 |
| RubyGems | activestorage | 7.2.3.1 | GHSA-r46p-8f7g-vvvg |
| RubyGems | activestorage | 8.1.2.1 | GHSA-r46p-8f7g-vvvg |
| RubyGems | activestorage | 8.0.4.1 | GHSA-r46p-8f7g-vvvg |
| Ubuntu:24.04:LTS | rails | no fix listed | UBUNTU-CVE-2026-33174 |
| Ubuntu:25.10 | rails | no fix listed | UBUNTU-CVE-2026-33174 |
| Ubuntu:26.04:LTS | rails | no fix listed | UBUNTU-CVE-2026-33174 |
| Ubuntu:26.10 | rails | no fix listed | UBUNTU-CVE-2026-33174 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| rails | activestorage | >= 8.1.0.beta1, < 8.1.2.1>= 8.0.0.beta1, < 8.0.4.1< 7.2.3.1 |
Weakness: CWE-789 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U
References
- https://github.com/rails/rails/security/advisories/GHSA-r46p-8f7g-vvvg x_refsource_CONFIRM
- https://github.com/rails/rails/commit/2cd933c366b777f873d4d590127da2f4a25e4ba5 x_refsource_MISC
- https://github.com/rails/rails/commit/42012eaaa88dfc7d0030161b2bc8074a7bbce92a x_refsource_MISC
- https://github.com/rails/rails/commit/8159a9c3de3f27a2bcf2866b8bf9ceb9075e229b x_refsource_MISC
- https://github.com/rails/rails/releases/tag/v7.2.3.1 x_refsource_MISC
- https://github.com/rails/rails/releases/tag/v8.0.4.1 x_refsource_MISC
- https://github.com/rails/rails/releases/tag/v8.1.2.1 x_refsource_MISC